Laboratory Chemistry of the

Outer Solar System

Marla MooreNASA/Goddard Space Flight Center

January 28, 2008

Cosmic Ice Lab Cosmic Ice Lab

Polar Gateways Arctic Circle Sunrise 2008, Barrow Alaska

What we do ?Laboratory radiation chemistry of relevant outer solar system ices.

What we need!A good understanding of outer solar system environments, e.g.:

TemperatureRadiation environment

Ice composition of surfaces

Laboratory Chemistry GoalHelp explain observations and predict likely new products yet to

be discovered

50 years ago

Explorer I. January 31, 1958

Temperature – calculated – assuming black bodies T ≈ 300 r -1/2

Radiation environment

Cosmic ray energy spectrum of primary cosmic rays was known

Launch of Explorer I— discovery of Van Allen radiation belts

e.g. Pluto 55 K

50 years agoIce Composition Near-Infrared water-ice feature detected on:

Mars polar capRings of SaturnEuropa and GanymedeSuspected water ice on inner satellites of Saturn

based on reflectivity

Laboratory radiation chemistry

1953 (origin of life study) gas phase mixtures

1957-1960 (rocket fuel?)Frozen free radicalexperiments

1963 ( comets)77 K mixture H2O+CH4+NH3

5 MeV electrons

John Oro

Gerald Kuiper

Some Ice

Environments

KBOs

water

carbon dioxide ammonia

methanenitrogencarbon monoxide

Earth H2O Mars H2O Jupiter Io Europa H2O

Ganymede H2O

Callisto

Saturn Mimas H2O Hyperion

Enceladus H2O Iapetus Tethys H2O Phoebe Dione Titan Rhea Rings H2O Uranus Miranda Ariel

Titania

Umbriel Oberon Neptune Triton Pluto

Earth H2O Mars H2O, CO2 Asteroids H2O, also ice containing a CH IR signature Jupiter Io SO2, SO3, H2S?, H2O? Europa H2O, SO2, SH, CO2, CH,

XCN, H2O2, H2SO4, carbonate salt, hydrous sulfate

Ganymede H2O, SO2, SH, CO2, CH, XCN, O2, O3, hydrated and hydroxylated minerals

Callisto H2O, SO2, SH, CO2, CH, XCN, hydrated and hydroxylated minerals

Saturn Mimas H2O Hyperion H2O Enceladus H2O Iapetus H2O, C, HC, H2S? Tethys H2O Phoebe H2O, CO2, CH,

XCN Dione H2O, C, HC, O3 Titan H2O, C2(CH)2 Rhea H2O, HC?, O3 Rings H2O Uranus Miranda H2O, NH3 hydrate, hydroxylated silicates Ariel H2O, CO2,

OH? Titania H2O, C, HC, OH?

Umbriel H2O Oberon H2O, C, HC, OH? Neptune Triton N2, CH4, CO, CO2, H2O Pluto N2, CH4, CO, H2O, C2H6 Charon H2O, NH3, (NH3 hydrate?) Kuiper Belt Objects H2O seen on some KBOs; NH3 is seen on

Quaoar

*

**

Based onTable 4 from T. Roush, JGR, 2001

*

WaterMethaneAmmonia

Carbon Monoxide Carbon Dioxide

Methane Methyl Alcohol Formaldehyde

Ammonia Formic Acid

Hydrogen Sulfide Hydrogen Cyanide

Acetylene Ethane

Thioformaldehyde Cyanoacetylene

Formamide Methyl Formate Methyl Cyanide

Carbon Disulfide Sulfur Dioxide

Sulfur Monoxide Isocyanic Acid Ethylene Glycol

Radiolysis

Photolysis

/Magnetospheric

 

How do we study ices in the laboratory ?

     

      

Ice at 10 K

Vacuum

Infrared Spectrum

Infrared Light

Laboratory Set-Up

MeV p+10−7 mm Hg

H2O

CO2NH

3

Gas

p+

IR

Spectrometer

UV

Examples

1. H2O2 and sulfur--Europa

2. Fate of methane--Pluto

3. If methanol then sugar ? --Comets

•       

      

EUROPA

10-2

10-2 10-1 100 101 102

Energy MeV

H2O, SO2, SH, CO2, CH,XCN, H2O2, H2SO4, carbonate salt, hydrous sulfate

Laboratory ice studies used to: IDENTIFY

Hydrogen Peroxide on Europa

400800120016002000

-1

0

1

2

3

4

5

65 10 15 20

Wavenumber (cm-1)

Re

lativ

e A

bso

rba

nce

(a) 86 K

(c) 180 K

(e) 210 K

(d) 200 K H2SO4

monohydrate (ref.)

(f) 260 K

Wavelength (m)

(b) 175 K

x 2

x 2.5

x 2

600800100012001400160018002000-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.05 10 15 20

SO2

SO2

SO2-4

HSO-3

HSO-4

Rel

ativ

e A

bsor

banc

e

Wavenumber (cm-1)

H2O + SO2

86 K

SO2

H3O+

(a)

(b)

(c)

(d)

Wavelength (m)

H2O + SO2 Sulfuric acidp+

Laboratory ice studies shows that on Europa

The dashed curve shows the spectrum of a mixture of C2H2:C2H6:CH4 (Sasaki et al., 2005)

PLUTO

N2

CH4-methaneCO

Irradiated methaneforms ethaneand propane

Pluto spectrum

COMETHALE-BOPP

Carbon Monoxide Carbon Dioxide

Methane Methyl Alcohol Formaldehyde

Ammonia Formic Acid

Hydrogen Sulfide Hydrogen Cyanide

Acetylene Ethane

Thioformaldehyde Cyanoacetylene

Formamide Methyl Formate Methyl Cyanide

Carbon Disulfide Sulfur Dioxide

Sulfur Monoxide Isocyanic Acid Ethylene Glycol

H2O + CO, T= 15 K

(~108 yr)

Methanol

~ 10 K

H2Op+

OHOH

C O HCO H2COCH3O

CH2OHCH3OHH H H

HOCH2CH2OHCO2

H2CO3

HCOOH

HCOO

40%

7% 12%

20%

Ethylene Glycol

Discovered in 2002 in the ISM & in Comet Hale-Bopp

in 2004!(Hollis et al., 2000)

(Crovisier et al., 2004)

Methanol

Discovered in the ISM(Hollis et al., 2002)

C C H

OHH

OH

H

H

C C

H

OH

H

H

O

Ethylene Glycol Glycolaldehyde

p+

Looking to the future--------

Room temperature residues

New Tools for Chemical Analyses

HPLC & Detectors MS

Liquid ChromatographyMass Spectrometry

LC-MS

Gas ChromatographyMass Spectrometry

GC-MS

MSGC

New Horizons will reachthe Pluto system in July 2015

The ESA Rosetta spacecraft will reachcomet 67P/Churyumov-Gerasimenko in 2014

•Radiation processing complex molecules, and ions

•Reactions generally understood

•Laboratory work predicts new molecules and ions awaiting detection

SUMMARY

Reggie Hudson

Collaborators

Reggie Hudson

Robert Ferrante

Paul Cooper

Reggie Hudson

Reggie Hudson

Robert Ferrante

Paul Cooper

www-691.gsfc.nasa.gov/cosmic.ice.lab

2 3 4 5 6 7 8 9 10 11 12 13 H H2O NH3 CH4 CH3OH HC(O)CH3 CH3COOH (CH3)2O (CH3)2CO HC9N C6H6 HC11N

CO H2S H2CO SiH4 CH3SH c - C2H4O HC(O)OCH3 CH3CH2OH HOCH2CH2OH CO(CH2OH)2? CSi HCN H2CS CH2NH C2H4 CH2CH(OH) HOCH2C(O)H CH3CH2CN C2H5C(O)H CP HNC C2H2 NH2CN H(CC)2H CH3CCH CH3CCCN CH3C4H CH3(CC)2CN CS CO2 HNCO CH2CO CH3CN CH3NH2 H2C6 HC7N NO SO2 HNCS HCOOH CH3NC CH2CH(CN) H(CC)3H C8H NS MgCN H3O+ HCCCN HC(O)NH2 H(CC)2CN C2H3C(O)H SO MgNC SiC3 HCCNC HCCC(O)H C6H C7H HCl NaCN C3S c - C3H2 HC3NH+ NaCl N2O H2CN l - C3H2 HC4N KCl NH2 c - C3H CH2CN C5N AlCl OCS l - C3H H2COH+ C5H AlF CH2 HCCN C4Si H2CCCC PN HCO CH3 C5 C4H SiN C3 C2CN HNCCC SiO C2H C3O SiS C2O HCNH+ NH C2S HOCO+ OH AlNC C2 HNO CN SiCN HF N2H+ FeO SiNC LiH

c - SiC2

CH HCO+ CH+ HOC+ CO+ HCS+ SO+ H3

+ SH OCN− N2

O2 ?